1. Field of the Invention
This invention relates to a disposable cuvette for holding a test sample or specimen, reagent, and diluent while performing a test in an automated machine, primarily for medical diagnostic purposes. The disposable cuvette can be prepackaged with a dry reagent to which a diluent is added during a test or with a liquid reagent thereby eliminating the need for the addition of a diluent in an automated test machine.
2. Description of the Prior Art
Cuvettes utilized for manual or automated medical testing are well known. In general, a procedure is established to measure the emergent wavelength of radiant energy absorbed by a sample under analysis. In a manual test, typically a technician loads a cuvette with a sample, reagent and diluent necessary to accomplish the test, each ingredient being precisely measured. The contents are mixed and the emergent radiation is observed optically or ocularly. Because the kind and precise quantity of reagent and diluent employed are critical to a successful test result, technician time and expertise to prepare and use cuvettes are significant factors to be considered with regard to cost, human error, and emergency diagnosis. Preparation time has also become a significant factor with the introduction of automated medical diagnostic machines. Such machines and their corresponding cuvettes have attempted to reduce preparation time by prepackaging various reagents and/or diluents in a container that itself ultimately houses a test performed therein. U.S. U.S. Pat. No. 3,504,376 issued Mar. 30, 1970 to Bednar et al. shows such a system.
A significant factor in the use of automated test equipment is that the reagent and the diluent must be mixed prior to the addition of the sample so that the emergent radiation from the reagent diluent mixture can provide a baseline measurement that is compared to the emergent radiation from the mixture that includes the sample. This factor precludes mixing the sample at the same time the diluent is added to the reagent. In the present invention, the sample or specimen is manually loaded in a separate chamber in the cuvette where it remains until after the reagent and diluent have been mixed and the baseline measurement of the reagent-diluent taken. The use of automated diagnostic test equipment still requires that all ingredients necessary for a specific test be precisely measured regardless of whether the cuvette is preloaded at the factory or loaded at the test site.
The use of multiple, separated compartments in testing vessels with automated machines is shown in U.S. Pat. No. 3,504,376 issued to Bednar et al on Mar. 31, 1970 (cited above); U.S. Pat. No. 4,458,020 issued to Bohn et al. on Jul. 3, 1984; and U.S. Pat. No. 4,473,530 issued to Villa-Real on Sep. 25, 1984. Each vessel shown is a complex in physical structure and requires complex interaction with the test equipment for operation.
Disposal of test containers having the residual samples and reagents therein poses a significant environmental waste problem. Washing and reusing a cuvette is not a good practice because the test results could be affected by a poorly washed cuvette. With the present invention, the cuvette remains sealed after the test and is not reusable.
As the use of prepackaged cuvettes increases in volume, reducing the cost of the manufacture and factory loading of the cuvette also becomes important.